Light-source device and display device

ABSTRACT

A light source device has a light emitting element, a light guide plate which light from the light emitting element enters, and wiring which extends from the light emitting element side along the edge (a second side surface or a third side surface) of the light guide plate and supplies power to the light emitting element. The light guide plate has a stopper which is located on an arrangement side of the wiring from the light emitting element and which restricts movement of the light emitting element to the arrangement side of the wiring.

FIELD OF INVENTION

The present invention relates to a light source device and a displaydevice which has the light source device

BACKGROUND

There is known a light source device having a light source and a lightguide plate for converting light from the light source to planar light(for example Patent Literature 1). Such a light source device is forexample being used in a display device such as a liquid crystal displaydevice. To the light source, wiring for supplying power to the lightsource is connected. The wiring is suitably laid and for example extendsto the outside of the light source device or display device.

PRIOR ART DOCUMENTS Patent Literature

-   Patent Literature 1: Japanese Patent Publication No. 2002-133933A

SUMMARY Technical Problem

The wiring is easily subjected to tension at the time of assembly orafter assembly. The tension causes positional deviation of the lightsource with respect to the light guide plate. As a result, in the lightsource device, the desired luminance or uniformity of the luminance isliable to not be obtained.

Accordingly, it is desired to provide a light source device whichenables positional deviation of the light source due to tension of thewiring to be suppressed and a display device which has the light sourcedevice.

Solution to Problem

A light source device according to an aspect of the present inventionhas a light source, a light guide plate which light from the lightsource enters, and wiring which extends from the light source side alongthe edge of the light guide plate and supplies power to the lightsource, wherein the light guide plate has a stopper which is located onthe arrangement side of the wiring from the light source and whichrestricts movement of the light source to the arrangement side.

A display device according to an aspect of the present invention has alight source, a light guide plate which light from the light sourceenters, a display panel to which the light of the light guide plate isirradiated, and wiring which extends from the light source side alongthe edge of the light guide plate and which supplies power to the lightsource, wherein the light guide plate has a stopper which is located onthe arrangement side of the wiring from the light source and whichrestricts movement of the light source to the arrangement side.

Advantageous Effects of Invention

According to the above configuration, positional deviation of the lightsource due to tension of the wiring can be suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 A perspective view of an appearance of a display device accordingto an embodiment of the present invention.

FIG. 2 A schematic disassembled perspective view of the display deviceof FIG. 1.

FIG. 3 A cross-sectional view taken along the line III-III of FIG. 1.

FIG. 4 A plan view of a light source device of the display device ofFIG. 1.

FIG. 5 A perspective view of a light source unit of the light sourcedevice of FIG. 4.

FIG. 6 A perspective view which shows the periphery of one light sourceunit.

FIG. 7 A perspective view which shows the periphery of another lightsource unit.

FIG. 8 A perspective view which shows enlarged the vicinity of wiring ofa light guide plate of the light source device of FIG. 4.

FIG. 9 A perspective view which shows enlarged a region IX of FIG. 8.

FIG. 10 A cross-sectional view taken along the line X-X of FIG. 9.

FIG. 11 A cross-sectional view taken along the line XI-XI of FIG. 9.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

An embodiment of the present invention will be explained below withreference to the drawings. Note that, the notations include the samenotations with additional notations of capital letters attached forparts of the same or similar configurations such as “first light sourceunit 13A, second light source unit 13B”. Further, in this case, thenumber of the head of the name and the above additional notation will besometimes omitted such as the “light source unit 13”.

FIG. 1 is a perspective view of an appearance of a display device 1according to an embodiment of the present invention.

The display device 1 is configured by for example a liquid crystaldisplay device which is capable of displaying an image on a displayscreen 1 a. The display device 1 has a housing 3. The housing 3 is forexample formed in a substantially thin rectangular parallelepiped shape.It has a first corner 3 a, second corner 3 b, third corner 3 c, andfourth corner 3 d and has a first side surface 3 ab, second side surface3 bc, third side surface 3 cd, and fourth side surface 3 da betweenthese corners. The display screen 1 a is provided on one major surfaceof the housing 3. The display screen 1 a for example has a roughlysimilar shape (rectangle in the present embodiment) as the major surfaceof the housing 3, but is provided at the major surface of the housing 3offset toward the first corner 3 a side.

FIG. 2 is a schematic disassembled perspective view of the displaydevice 1.

The display device 1 has a face board 5 and a back board 7 whichconfigure the housing 3. Further, the display device 1 has, inside thehousing 3, a display panel 9 and a light source device 11 as the backlight which illuminates the display panel 9.

The back board 7 is formed in for example a box shape which is capableof accommodating the light source device 11 and the display panel 9. Theface board 5 is formed in for example a box shape which is one sizelarger than the back board 7, is placed over the back board 7 whichaccommodates the light source device 11 and display panel 9, closes theopening of the back board 7, and surrounds the outer periphery of theback board 7. In the face board 5, a display window 5 a is opened forexposure of the display panel 9. The display window 5 a is provided atthe face board 5 offset toward the first corner 3 a side.

The face board 5 and back board 7 are formed by for example metal. Morespecifically, for example, the face board 5 and back board 7 areconfigured by press working sheet metal. Note, the face board 5 and backboard 7 may be formed by plastic as well. The face board 5 and backboard 7, while not particularly shown, are fixed to each other byengagement parts, screws, solder, and/or a binder.

The display panel 9 is configured by a so-called “liquid crystal displaypanel”. That is, the display panel 9 has two transparent substrateswhich are arranged facing each other and have a clearance between themin which a liquid crystal is sealed (liquid crystal display panel 9 a inthe narrow sense (see FIG. 3)) and polarizing plates 9 b laminated ontheir two surfaces. Although not particularly shown, pixel electrodes,common electrodes, color filters (in the narrow sense), etc. arelaminated on the two transparent substrates.

The display panel 9 is formed for example in a rectangular shape onesize larger than the display window 5 a. The display panel 9 is arrangedoffset toward the first corner 3 a side with respect to the majorsurface of the housing 3 in the same way as the display window 5 a andcloses the display window 5 a from the inside. The display screen 1 a isconfigured by a portion which is exposed from the display window 5 a ofthe display panel 9.

Although not particularly shown, the display panel 9 is connected to aflexible board (for example TAB tape), while the flexible board isconnected to a circuit board. On the circuit board, an IC for convertingdisplay information to a display signal is mounted. On the flexibleboard, a driver IC is mounted for supplying voltage between the pixelelectrodes and the common electrodes for each pixel based on the displaysignal from the IC. These flexible board and circuit board are arrangedon the second side surface 3 bc side and third side surface 3 cd side ofthe housing 3 with respect to the display panel 9. Note that, the driverIC etc. may be mounted on the display panel 9 by a COG technique aswell.

The light source device 11 has a first light source unit 13A and secondlight source unit 13B (see FIG. 4) which generate light, a light guideplate 15 for guiding the light which is generated by the light sourceunits 13, and first wiring 17A and second wiring 17B (see FIG. 4) forsupplying power to the light source units 13. Further, the light sourcedevice 11 has an optical sheet 19 and reflecting plate 21 for moreefficiently utilizing the light which is guided by the light guide plate15.

The light guide plate 15 is formed in for example a substantiallyrectangular flat plate shape and has a first major surface 15 e andsecond major surface 15 f. Further, the light guide plate 15 is formedby for example a light transmitting acrylic plate. On the second majorsurface 15 f, for example, provision is made of a not shown dot pattern(plurality of projecting portions) which is formed integrally with thelight guide plate 15 or formed by a member different from the lightguide plate 15.

The light source units 13 are configured as point light sources. Thelight source units 13 are arranged to face a side surface (includingcorners) of the light guide plate 15. More specifically, for example,the corners of the light guide plate 15 are chamfered, and the lightsource units 13 face the chamfered surfaces.

The light which is generated at the light source units 13 enters thelight guide plate 15 from the above-described chamfered surfaces (sidesurface of the light guide plate 15). The light which enters the sidesurface of the light guide plate 15 is totally reflected at the firstmajor surface 15 e and second major surface 15 f while being guidedalong these major surfaces. The guided light is scattered by the dotpattern and exits from the first major surface 15 e. In this way, thelight generated in the light source units 13 is converted to planarlight.

The optical sheet 19 is configured by for example laminating two prismsheets in which fine relief shapes are formed and is laminated on thefirst major surface 15 e. The prism sheets are formed by for example aresin such as a polyester or polycarbonate. The light which is emittedfrom the first major surface 15 e is given directivity when passingthrough the optical sheet 19. Due to this, the luminance of the lightsource device 11 is improved.

The reflecting plate 21 is formed in for example a box shape (however,not having a side surface on the third side surface 3 cd side) which iscapable of accommodating the light guide plate 15 and covers the secondmajor surface 15 f and side surfaces of the light guide plate 15. Thereflecting plate 21 is formed by for example a metal, a resin which iscoated by a metal, or a plastic which contains a scattering agent etc.The light which is leaked from the second major surface 15 f or sidesurface of the light guide plate 15 is reflected at the reflecting plate21 and enters the light guide plate 15 again. Due to this, the luminanceof the light source device 11 is improved.

The light guide plate 15 substantially fits in the reflecting plate 21.Further, the reflecting plate 21 which accommodates the light guideplate 15 substantially fits in the back board 7 (housing 3) (see FIG. 4too). Note that, the light guide plate 15 or reflecting plate 21 mayindirectly abut against the inner side surfaces of the housing 3 throughsuitable members. Further, the light guide plate 15, optical sheet 19,and reflecting plate 21 may be fixed to each other by suitable meanssuch as a binder.

FIG. 3 is a cross-sectional view taken along the line of FIG. 1.

As explained above, the housing 3 has the face board 5 and back board 7.Further, in the housing 3, from the display screen 1 a side, the displaypanel 9, optical sheet 19, light guide plate 15, and reflecting plate 21are laminated in that order. The light source units 13 are arranged toface the side surface of the light guide plate 15.

Note that, in the internal portion of the housing 3, provision is alsomade of a holding member 6 which fits in the clearance between the lightsource device 11, display panel 9, and other members and the housing 3and contributes to positioning of the members with respect to thehousing 3.

FIG. 4 is a plan view of the light source device 11. Note, illustrationof the optical sheet 19 is omitted. Further, the inner side surfaces ofthe housing 3 (back board 7) are indicated by a two-dotted chain line.Note that, the housing 3 (back board 7) may be grasped as a portion ofthe light source device 11 as well.

The light guide plate 15 is, as explained above, formed to asubstantially rectangular shape, has a first corner 15 a to fourthcorner 15 d which correspond to the first corner 3 a to fourth corner 3d of the housing 3, and has a first side surface 15 ab, second sidesurface 15 bc, third side surface 15 cd, and fourth side surface 15 dabetween these corners.

A display region 9 c (indicated by a one-dotted chain line) fordisplaying images of the display panel 9 or display window 5 a (FIG. 2)of the housing 3 is arranged offset toward the first corner 15 a sidewith respect to the first major surface 15 e of the light guide plate15. In other words, in the light guide plate 15, the outside area of thedisplay region 9 c becomes broader on the second side surface 15 bc andthird side surface 15 cd sides than the first side surface 15 ab andfourth side surface 15 da sides. Accordingly, the second side surface 15bc and third side surface 15 cd become portions in which the influenceof reflection etc. exerted upon the luminance of the display region 9 cis relatively lower compared with the first side surface 15 ab andfourth side surface 15 da. Note that, the display region 9 c is definedby for example a range of arrangement of pixels (pixel electrode).

The two light source units 13 are arranged to face corners at the twoends of one side of the light guide plate 15. Specifically, for example,the light source units 13 face the third corner 15 c and fourth corner15 d at the two ends of the shorter side (third side surface 15 cd) onthe side where the outside area of the display region 9 c is relativelylarge in the light guide plate 15.

The light source unit 13 irradiates light by a predetermined irradiationangle α in a generally diagonal direction of the light guide plate asthe irradiation direction. In the irradiation angle α, for example, arange of 50% of relative light intensity is defined as the irradiationangle. The magnitude thereof is for example 60 degrees.

The light which is generated by the light source unit 13 is uniformlytaken out from the first major surface 15 e by being guided, reflectedand scattered by the light guide plate 15 etc. However, it is hard forthe light to reach a region which is not contained within the range ofthe irradiation angle α (non-irradiation region) in the side surface ofthe light guide plate 15. Accordingly, the entire third side surface 15cd, the third corner 15 c side portion in the second side surface 15 bc,and the fourth corner 15 d side portion in the fourth side surface 15 dabecome portions in which the influence exerted upon the luminance of thedisplay region 9 c is relatively low compared with the other portions inthe side surface of the light guide plate 15.

The first wiring 17A is for supplying power to the first light sourceunit 13A. The first wiring 17A extends from the first light source unit13A (fourth corner 15 d) along the third side surface 15 cd up to thethird corner 15 c and further extends to the outside of the housing 3from a not shown hole formed around the third corner 3 c of the housing3. Accordingly, the first wiring 17A is provided along the side surfacehaving a relatively large distance from the display region 9 c and isprovided in a non-irradiation region of the light source unit 13.

The second wiring 17B is for supplying power to the second light sourceunit 13B. The second wiring 17B is arranged at a portion of the secondside surface 15 bc on the third corner 15 c side. Then, it merges withthe first wiring 17C and extends to the outside of the housing 3 from anot shown hole formed around the third corner 3 c of the housing 3.Accordingly, the second wiring 17B is provided along a side surfacehaving a relatively large distance from the display region 9 c and isprovided in a non-irradiation region of the light source unit 13.

At the tips of the plurality of wirings 17, a connector 18 is providedfor connecting the plurality of wirings 17 to another apparatus. Notethat, the plurality of wirings 17 may be bundled by a suitable member orthe insulation films of the wirings 17 may be bonded to each other atthe point where the first wiring 17A and second wiring 17B merge or at asuitable position and/or in a suitable range from the above point wherethey merge up to the connector 18.

FIG. 5 is a perspective view of a light source unit 13. Note that, partof the members such as the wirings 17 are schematically shown.

The light source unit 13 has a light emitting element 23 as the pointlight source, a substrate 25 on which the light emitting element 23 ismounted, and a heat dissipating plate 27 which holds the substrate 25.

The light emitting element 23 is configured by for example an LED, morespecifically is configured by a chip LED substantially rectangularparallelepiped.

The wiring 17 is for example formed by covering one or more metal wiresby an insulation film. Two wirings 17 are provided for one light sourceunit 13 corresponding to positive/negative potentials. Note that, thecross-sectional shape of the wiring 17 is generally circular, but isshown by a rectangle since FIG. 5 is a schematic diagram. Further, thecoating films of the two wirings 17 may be bonded to each other. Thecoating films may be given a suitable color. However, preferably a whitecolor is given so as to contribute to improvement of the luminance ofthe light guide plate 15, but so as to not exert any influence upon thechromaticity.

The substrate 25 is configured by a rigid type circuit board using hardresin or ceramic as the base or a flexible printed circuit board using acopper clad laminated board on one surface or two surfaces of apolyester film or polyimide film and has a mount surface 25 a on onemajor surface. The substrate 25 is formed to for example a rectangle.

On the mount surface 25 a, the light emitting element 23 issurface-mounted by solder, while the wirings 17 are connected by solder.The light emitting element 23 and the wirings 17 are electricallyconnected through a not shown wiring pattern of the substrate 25. Thelight emitting element 23 is mounted on for example one side of alongitudinal direction of the mount surface 25 a, while the wirings 17are connected to the other side of the longitudinal direction of themount surface 25 a and extend to the other side.

The heat dissipating plate 27 is for example formed by press working onesheet metal. The heat dissipating plate 27 has a back surface portion 27a which faces the back surface of the mount surface 25 a of thesubstrate 25, an extending portion 27 b which is perpendicular to theback surface portion 27 a, and a projection portion 27 c which projectsat the opposite side to the extending portion 27 b of the back surfaceportion 27 a, and faces the extending portion 27 b. In the extendingportion 27 b, a hole 27 h is formed as an empty space.

The substrate 25 is fixed to the heat dissipating plate 27 by forexample using solder, a binder, or double sided tape to bond the backsurface of the mount surface 25 a to the back surface portion 27 a. Notethat, the material or member bonding the substrate 25 and heatdissipating plate 27 preferably has a high thermal conductivity.

The projection portion 27 c can abut against one side surface thesubstrate 25 and contributes to restriction of movement of the substrate25. The restriction direction is for example a lateral direction of thesubstrate 25, a direction which is perpendicular to the arrangementdirection of the mount regions of the light emitting element 23 andwirings 17, and a direction which is perpendicular to the direction ofextension of the wirings 17.

Further, the substrate 25 is restricted in movement in the diametricaldirection of the hole 27 h with respect to the heat dissipating plate 27by having one side surface portion accommodated and preferably fit inthe hole 27 h. The restriction direction is for example a longitudinaldirection of the substrate 25, an arrangement direction of the mountregions of the light emitting element 23 and wirings 17, a direction ofextension of the wirings 17, and a direction which is perpendicular tothe restriction direction of the projection portion 27 c.

Note that, the side surface of the substrate 25 which is accommodated inthe hole 27 h (the side surface which faces downward in the sheetsurface of FIG. 5) preferably becomes the same plane as the surface ofthe extension portion 27 b which is at the opposite side to the backsurface portion 27 a (the surface which faces downward in the sheetsurface of FIG. 5).

Double sided tape 29 is arranged on the surface of the extending portion27 b on the back surface portion 27 a side. More specifically, thedouble sided tape 29 is arranged on the side of the tip end of theextending portion 27 b other than the hole 27 h. Further, as shown inFIG. 3, the double sided tape 29 is bonded to the back surface of thereflecting plate 21 (the surface opposite to the light guide plate 15)whereby the heat dissipating plate 27 is fixed to the reflecting plate21 and light guide plate 15. Note that, a binder or solder may be usedin place of the double sided tape 29.

As shown in FIG. 3, the extending portion 27 b abuts against the innerside surface of the back board 7. Further, the portion of the substrate25 accommodated in the hole 27 h abuts against the inner side surface ofthe back board 7 as well. Due to this, heat of the substrate 25 isindirectly through the heat dissipating plate 27 or directly transmittedto the back board 7.

FIG. 6 is a perspective view which shows the periphery of the firstlight source unit 13A.

When viewed by a plane, a cut-away portion is formed in the fourthcorner 15 d (chamfered surface) of the light guide plate 15. The firstlight source unit 13A is arranged so as to be accommodated in thiscut-away portion and is restricted in movement with respect to the lightguide plate 15. In other words, the light guide plate 15 has a lightguide plate body 15 q which includes a facing surface 15 r which thefirst light source unit 13A faces in its side surface, and a stopper 15s and positioning portion 15 t which project from the light guide platebody 15 q and restrict the movement of the first light source unit 13A.

The stopper 15 s is located on the arrangement side of the first wiring17A with respect to the first light source unit 13A (or light emittingelement 23) and restricts movement of the first light source 13A (orlight emitting element 23) to the arrangement side of the first wiring17A. More specifically, the stopper 15 s is formed so as to project tothe back surface side (the side of the inmost part of the sheet surfaceof FIG. 6) of the light guide plate body 15 q as well, and the edge ofthe extending portion 27 b of the heat dissipating plate 27 abutsagainst the stopper 15 s.

The positioning portion 15 t is located on the opposite side to thearrangement side of the first wiring 17A with respect to the first lightsource unit 13A (or light emitting element 23) and restricts movement ofthe first light source 13A (or light emitting element 23) to theopposite side to the arrangement side of the first wiring 17A. Morespecifically, the positioning portion 15 t is formed with a thicknessequivalent to that of the light guide plate body 15 q, and the edge ofthe back surface portion 27 a of the heat dissipating plate 27 abutsagainst the positioning portion 15 t.

The stopper 15 s and positioning portion 15 t are formed integrally withthe light guide plate body 15 q for example by forming shapescorresponding to the stopper 15 s and positioning portion 15 t in themold for injection molding the light guide plate 15.

Note that, the light source unit 13, stopper 15 s, and positioningportion 15 t are contained in a rectangle when assuming that the lightguide plate 15 is not provided with chamfered surfaces and the cut-awayportion. As shown in FIG. 4, they are contained in the rectangularhousing 3 in which the light guide plate 15 substantially fits.

Further, in the facing surface 15 r, a step is formed in order tosuppress interference between the wirings 17 and the light guide plate15 while making the light emitting element 23 abut against the facingsurface 15 r. However, a step need not be formed, and the light emittingelement 23 need not abut against the facing surface 15 r.

FIG. 7 is a perspective view which shows the periphery of the secondlight source 13B.

On the second light source unit 13B side as well, in the same way as thefirst light source unit 13A side, a stopper 15 s and positioning portion15 t are provided. The configurations of the stopper 15 s andpositioning portion 15 t on the second light source unit 15B side arethe same as those of the stopper 15 s and positioning portion 15 t onthe first light source unit 13A side explained above.

FIG. 8 is a perspective view which shows enlarged the vicinity of thewirings 17 of the light guide plate 15.

The light guide plate 15 has a first guide part 31A for positioning thefirst wiring 17A and a second guide part 31B for positioning the secondwiring 17B. The guide parts 31 are formed integrally with the otherparts of the light guide plate 15 for example by forming shapescorresponding to the guide parts 31 in the mold for injection moldingthe light guide plate 15.

FIG. 9 is a perspective view which shows enlarged a region IX of FIG. 8.

As shown in FIG. 8 and FIG. 9, the first guide part 31A is providedalong the third side surface 15 cd of the light guide plate 15 (it isalso possible to grasp that the first guide part 31A configures thethird side surface 15 cd) and guides the first wiring 17A along thethird side surface 15 cd.

More specifically, the first guide part 31A has a groove portion 31 awhich extends along the third side surface 15 cd. The first wiring 17Ais guided by being accommodated in the groove portion 31 a.

The groove portion 31 a has first concave grooves 31 b which are formedin the first major surface 15 e of the light guide plate 15 and secondconcave grooves 31 c which are formed in the second major surface 15 f.The first concave grooves 31 b and the second concave grooves 31 c arealternately provided in a direction along the third side surface 15 cd(the arrangement direction of the first wiring 17A) and connected.

More specifically, from the first light source unit 13A side to thesecond light source 13B side, a first concave groove 31 b, secondconcave groove 31 c, first concave groove 31 b, second concave groove 31c, and first concave groove 31 b are provided in that order. These firstconcave grooves 31 b and second concave grooves 31 c are for examplearranged substantially symmetrically about the center of the third sidesurface 15 cd. For example, a first concave groove 31 b is located atthe center of the third side surface 15 cd, second concave grooves 31 care located on the two sides of that at positions and with lengths whichare roughly equal, and, further, first concave grooves 31 b are locatedon their two sides.

In the first guide part 31A, a slit 31 s is formed which penetrates fromthe first major surface 15 e to the second major surface 15 f. The slit31 s is formed with a width that allows the first wirings 17A (at leastone of them) to pass therethrough, connects with the first concavegrooves 31 b, and runs parallel to the second concave grooves 31 c. Theportion of the slit 31 s which runs parallel to the second concavegrooves 31 c is located inside the major surface of the light guideplate 15 from the second concave grooves 31 c.

Note that, in the present embodiment, the portions of the slit 31 swhich run parallel to the second concave grooves 31 c open to the bottomof the second concave grooves 31 c. The width capable of passing thefirst wiring 17A does not always have to be larger than the diameter ofthe first wiring 17A, but may be a width capable of passing the firstwiring 17A while resiliently deforming its coating film.

At first, the first wiring 17A is accommodated in the first concavegrooves 31 b and is passed through the slit 31 s from the first majorsurface 15 e side. Then, the first wiring 17A is positioned by the firstconcave grooves 31 b and second concave grooves 31 c by the portionswhich have passed through the slit 31 s being moved to the outside ofthe major surface of the light guide plate 15.

FIG. 10 is a cross-sectional view taken along the line X-X of FIG. 9.FIG. 11 is a cross-sectional view taken along the line XI-XI of FIG. 9.

The first concave grooves 31 b and second concave grooves 31 c whichwere explained above can be grasped from another viewpoint. That is, itcan be grasped that the first guide part 31A has first locking portions31 d which can abut against the first wiring 17A from one lateral side(the second major surface 15 f side) and second locking portions 31 ewhich can abut against the first wiring 17A from the other lateral side(first major surface 15 e side). Further, the first locking portions 31d and the second locking portions 31 e are alternately arranged in theextending direction of the first wiring 17A. Further, the first guidepart 31A has third locking portions 31 j and a light guide plate body 15q which are arranged over the arrangement positions of the first lockingportions 31 d and second locking portions 31 e and abut against thefirst wiring 17A in the direction perpendicular to the abutmentdirection of the first locking portions 31 d and the second lockingportions 31 e.

Viewed in the extending direction of the first wiring 17A, a gap “d”between a first locking portion 31 d and a second locking portion 31 e(gap between the bottom surface of the first concave groove 31 b and thebottom surface of the second concave groove 31 c) is narrower than thediameter of one first wiring 17A. Accordingly, the first wiring 17A ispositioned by the first locking portion 31 d and second locking portion31 e so as to meander somewhat.

Note that, a projecting ridge 15 j which is located at the inner side ofthe major surface of the light guide plate 15 from the first guide part31A (see FIG. 9 too) is for positioning the optical sheet 19 by abutmentagainst an edge of the optical sheet 19. Note the projecting ridge 15 jmay be arranged at another position and be broadened to a position whereit closes the first concave groove 31 b and slit 31 s as well.

FIG. 7 which has been already referred to is also a perspective viewwhich shows the second guide part 31B enlarged.

The second guide part 31 b has a thin portion 31 f in which the surfaceon the first major surface 15 e side becomes lower than the light guideplate body 15 q and a projection portion 31 g which projects from thethin portion 31 f to the direction faced by the first major surface 15e.

The projection portion 31 g is mostly located in the direction along thesecond side surface 15 bc with respect to the second light source unit13B. The planar shape of the projection portion 31 g may be suitablyset, but is for example a roughly rectangular shape having a directionalong the second side surface 15 bc as the longitudinal direction.

Further, the second wiring 17B extends, on the thin portion 31 f, fromthe second light source unit 13B side to the projection portion 31 gside along the second side surface 15 bc. After that, it circles aroundthe projection portion 31 g at a predetermined angle (180 degrees in thepresent embodiment). The second wiring 17B is turned back and positionedby circling around the projection portion 31 g. The turned second wiring17B extends along the second side surface 15 bc again, but from theprojection portion 31 g side to the second light source unit 13B sidethis time.

Between the projection portion 31 g and the light guide plate body 15 q,a third concave groove 31 h is formed along a portion of the outerperiphery of the projection portion 31 g. Note that, a portion of thethird concave groove 31 h extends along the second side surface 15 bc,while another portion is perpendicular to the second side surface 15 bc.The third concave groove 31 h positions the second wiring 17B byaccommodating the second wiring 17B. The third concave groove 31 h isclosed by the optical sheet 19 (indicated by the two-dotted chain line).

Note that, the thin portion 31 f for arranging the second wiring 17 b isconnected to or shared with the stopper 15 s on the second light sourceunit 13B side. The two ends of the first guide part 31A are connected toor shared with the stopper 15 s (FIG. 6) on the first light source unit13A side and the positioning portion 15 t (FIG. 7) on the second lightsource unit 13B side.

According to the above embodiment, from a first viewpoint, the lightsource device 11 has the light emitting element 23, the light guideplate 15 which the light from the light emitting element 23 enters, andwirings 17 which supply power to the light emitting element 23, whilethe light guide plate 15 has the guide parts 31 for positioning thewirings 17.

Accordingly, the wirings 17 are positioned with respect to the lightguide plate 15. As a result, for example, the drop in work efficiencydue to free movement of the wirings 17 with respect to the light guideplate 15 is suppressed. Further, for example, the wirings 17 are keptfrom being caught between unintended members and given stress. That is,the wirings 17 are suitably arranged with respect to the light guideplate 15. The guide parts 31 are provided on the light guide plate 15,therefore the number of members does not increase either.

The first guide part 31A includes a groove portion 31 a which extendsalong the edge of the light guide plate 15 and accommodates the firstwiring 17A.

Accordingly, the first guide part 31A can arrange the first wiring 17Aat the outer circumferential side of the light guide plate 15 to reducethe influence of the first wiring 17A upon the luminance etc. whileaccommodating the first wiring 17A and keeping the first wiring 17A frombeing caught between the light guide plate 15 and another member (forexample, the housing 3) and thereby protect the first wiring 17A.Further, since the first wiring 17A is kept from being caught betweenthe light guide plate 15 and the housing 3, the work of fitting thelight source device 11 in the back board 7 is facilitated as well.

The first guide part 31A has a first locking portion 31 d which can abutagainst the first wiring 17A from one lateral side and a second lockingportion 31 e which can abut against the first wiring 17A from anotherlateral side.

Accordingly, the first wiring 17A can be reliably positioned in the twodirections of one lateral side and another lateral side.

First locking portions 31 d and second locking portions 31 e arealternately arranged in the extending direction of the first wiring 17A.

Accordingly, compared with the case where a first locking portion 31 dand a second locking portion 31 e face each other while sandwiching thefirst wiring 17A therebetween, positioning in two ways as explainedabove can be carried out while suppressing application of excessive load(compressive load) to the first wiring 17A, and error or design changerelating to the diameter of the first wiring 17A can be flexibly copedwith.

When viewed in the extending direction of the first wiring 17A, the gap“d” between a first locking portion 31 d and a second locking portion 31e is narrower than the diameter (width of cross-section) of the firstwiring 17A.

Accordingly, bidirectional positioning of the first wiring 17A can bereliably carried out by utilizing the resistance against bending of thefirst wiring 17A while avoiding excessive compressive load as explainedabove. Further, the first wiring 17A more reliably abuts against thefirst locking portion 31 d and second locking portion 31 e, therefore anincrease of frictional resistance of the first wiring 17A against thetension is expected as well.

The first guide part 31A has the first concave grooves 31 b which areformed in one major surface (first major surface 15 e) of the lightguide plate 15 and accommodate the first wiring 17A and the secondconcave grooves 31 c which are formed in the other major surface (secondmajor surface 15 f) of the light guide plate 15 and accommodate thefirst wiring 17A.

Accordingly, this means positioning of the first wiring 17A is performedin all directions of the diameter direction, so free movement of thefirst wiring 17A is more reliably suppressed.

The first concave grooves 31 b and second concave grooves 31 c arealternately arranged and connected in the extending direction of thefirst wiring 17A.

Accordingly, in the same way as the effect by the alternate arrangementof first locking portions 31 d and second locking portions 31 e, it ispossible to suppression application of excessive load (compressive load)by the bottom surfaces of the first concave grooves 31 b and the bottomsurfaces of the second concave grooves 31 c while positioning by thesebottom surfaces. Further, error or design changes relating to thediameter of the first wiring 17A can be flexibly coped with as well.

In the light guide plate 15, the slit 31 s is formed with a widthcapable of passing the first wiring 17A therethrough, penetrates fromthe first major surface 15 e to the second major surface 15 f, andextends while connected with the first concave grooves 31 b and runsparallel to the second concave grooves 31 c.

Accordingly, as already explained, the first wiring 17A is not moved inits extending direction to insert it in the first concave grooves 31 band second concave grooves 31 c. Rather, the first wiring 17A can bemoved in its diametrical direction to accommodate it in the firstconcave grooves 31 b and second concave grooves 31 c. That is, the firstwiring 17A can be simply arranged in the first concave grooves 31 b andsecond concave grooves 31 c.

The light source units 13 are individually provided at the third corner15 c and at the fourth corner 15 d on the two ends of one side of theedge of the light guide plate 15 (the third side surface 15 cd). Thefirst concave grooves 31 b and second concave grooves 31 c guide thefirst wiring 17A which extends from the first light source unit 13A sideto the second light source unit 13B side along the third side surface 15cd and which supplies power to the first light source unit 13A. The slit31 s is located inside the major surface of the light guide plate 15from the second concave grooves 31 c. In the direction along the thirdside surface 15 cd, a first concave groove 31 b is located at thecenter, and second concave grooves 31 c and the slit 31 s are providedon the two sides thereof.

Accordingly, compared with the combination of the second concave grooves31 c and slit 31 s, a first concave groove 31 b having a low liabilityof relatively lowering the luminance of the display region 9 c isarranged at the farthest position from the two light source units 13. Asa result, suppression of a local drop of the luminance is expected.Further, by the second concave grooves 31 c and the slit 31 s which arearranged on the two sides of the first concave groove 31 b, equalizationof the luminance at the two sides of the first concave groove 31 b andreliable positioning of the first wiring 17A at the two light sourceunits 13 are expected.

The second guide part 31B has a projection portion 31 g which changesthe direction of the second wiring 17B by the second wiring 17B circlingaround it.

Accordingly, positioning simply changing the direction of extension ofthe second wiring 17B becomes possible. Further, when tension is appliedto the second wiring 17B, part or all of the tension is cancelled by thefrictional resistance of the projection portion 31 g and transmission ofthe tension up to the tip is suppressed. As a result, for example, theconnection portion of the second wiring 17B and the second light sourceunit 13B can be protected.

The second wiring 17B extends along the edge of the light guide plate 15(second side surface 15 bd), circles the projection portion 31 b, andextends again along the edge.

Accordingly, by the second wiring 17B circling so as to turn back, theeffect of suppressing transmission of tension described above isreliably obtained. Further, since such turn back is performed along theedge of the light guide plate 15, it is possible to arrange the secondwiring 17B on the outer circumferential side of the light guide plate 15to reduce the influence which is exerted upon the luminance whilesecuring space for the second wiring 17B to turn back.

The guide parts 31 are arranged in the non-irradiation region of thelight emitting element 23 (the portion on the third side surface 15 cdside etc.)

Accordingly, the influence of the guide parts 31 or the wirings 17positioned by the guide parts 31 upon the luminance is reduced. Further,in the light guide plate 15, the non-irradiation region of the lightemitting element 23 is the region which becomes “dead space” since theinfluence exerted upon the improvement of luminance of the displayregion 9 c is low and effective utilization of such a region isachieved.

The light source device 11 further has the optical sheet 19 which islaminated on the first major surface 15 e of the light guide plate 15and transmits the light from the light guide plate 15 therethrough. Thesecond guide part 31B includes a third concave groove 31 h which isprovided in the first major surface 15 e and which accommodates thesecond wiring 17 b. The optical sheet 19 closes the third concave groove31 h.

Accordingly, the optical sheet 19 is also used as the member suppressingdetachment of the second wiring 17B from the third concave groove 31 h.That is, the second wiring 17B can be more reliably positioned whiledecreasing the number of the members.

The display device 1 has the light emitting element 23, the light guideplate 15 which the light from the light emitting element 23 enters, thedisplay panel 9 to which the light guided by the light guide plate 15 isirradiated, and the wirings 17 supplying power to the light emittingelement 23. The light guide plate 15 has the guide parts 31 forpositioning the wirings 17. Accordingly, in the display device 1 aswell, the advantageous effect of the light source device 11 of the firstaspect is exhibited.

The display panel 9 is a liquid crystal display panel. The displayregion 9 c of the liquid crystal display panel is provided offset withrespect to the major surface of the light guide plate 15. The guideparts 31 are formed along the edge among the edges of the light guideplate 15 which have a large distance from the display region 9 c (thesecond side surface 15 bc or third side surface 15 cd).

Accordingly, the influence of the guide parts 31 or the wirings 17positioned by the guide parts 31 exerted upon the luminance of thedisplay region 9 c is reduced. Further, in the light guide plate 15, theregion having a large distance from the display region 9 c is the regionwhich becomes “dead space” since the influence exerted upon theimprovement of luminance of the display region 9 c is low and effectiveutilization of such region is achieved.

Further, according to the above embodiment, from a second viewpoint, thelight source device 11 has the light emitting element 23, the lightguide plate 15 which the light from the light emitting element 23enters, and wirings 17 which extend from the light emitting element 23side along the edge of the light guide plate 15 (the second side surface15 bc or third side surface 15 cd) and which supply power to the lightemitting element 23. The light guide plate 15 has a stopper 15 s whichis located on the wiring 17 arrangement side with respect to the lightemitting element 23 and restricts the movement of the light emittingelement 23 to the arrangement side of the wirings 17.

Accordingly, even when tension is applied to the wirings 17, positionaldeviation of the light emitting element 23 with respect to the lightguide plate 15 can be suppressed. As a result, a drop of the luminanceor a drop of the uniformity of luminance in the light guide plate 15 issuppressed. Further, the stopper 15 s is formed at the light guide plate15, therefore an increase of the number of the members does not occur,and utilization of the light which leaks sideward from the lightemitting element 23 and is reflected by the stopper 15 s is expected aswell.

The light guide plate 15 has the positioning portion 15 t which islocated on the opposite side to the arrangement side of the wiring 17from the light emitting element 23 and restricts movement of the lightemitting element 23 to the opposite side.

Accordingly, the positional deviation of the light emitting element 23is more reliably suppressed. Further, the positioning portion 15 t isformed at the light guide plate 15 in the same way as the stopper 15 s,therefore an increase of the number of the members does not occur, andutilization of the light which leaks sideward from the light emittingelement 23 and is reflected or the like is expected as well.

The light guide plate 15 has the projection portion 31 g around whichthe second wiring 17B is circles so that the second wiring 17B extendingfrom the light emitting element 23 side of the second light source unit13B turns back to the light emitting element 23 side.

Accordingly, even if tension is applied to the end on the outer side ofthe second wiring 17B, transmission of the tension to the light emittingelement 23 is suppressed by the frictional resistance received from theprojection portion 31 g, the positional deviation of the light emittingelement 23 is further suppressed. Further, such a projection portion 31g is formed on the light guide plate 15, therefore an increase of thenumber of the members does not occur either.

The light source device 11 further has the optical sheet 19 which islaminated on the first major surface 15 e of the light guide plate 15and transmits the light from the light guide plate 15 therethrough. Inthe light guide plate 15, the third concave groove 31 h foraccommodating the second wiring 17B is formed in the first major surface15 e. The projection portion 31 g is configured in the partial region byextension of the third concave groove 31 h so as to separate the partialregion of the first major surface 15 e from the other regions. Theoptical sheet 19 closes the third concave groove 31 h.

Accordingly, the optical sheet 19 is used also as the member suppressingdetachment of engagement of the second wiring 17B with respect to theprojection portion 31 g. That is, the transmission of the tension of thesecond wiring 17B can be more reliably suppressed while decreasing thenumber of the members.

The light source device 11 further has a substrate 25 on which the lightemitting element 23 and wirings 17 are mounted and a heat dissipatingplate 27 which holds the substrate 25. The stopper 15 s abuts againstthe heat dissipating plate 27 and restricts the movement of the lightemitting element 23.

Accordingly, compared with the case where a stopper capable of abuttingagainst a very small light emitting element 23 while avoiding thesubstrate 25 and heat dissipating plate 27 is formed (this case isincluded in the invention of the present application as well), theconfiguration of the stopper 15 s can be made simple. Further, micromachining is unnecessary.

The heat dissipating plate 27 has an extending portion 27 b which islocated on one side of the direction faced by the light guide plate 15further than the light guide plate 15 and extends parallel to the lightguide plate 15. In the extending portion 27 b, a hole 27 h accommodatingat least a portion of the substrate 25 is formed.

Accordingly, the extending portion 27 b for increasing the heatdissipation area can be used to position the substrate 25 with respectto the heat dissipating plate 27, and a reduction of size of the lightsource unit 13 (reduction of thickness of the light source device 11) bythe amount of overlap of the extending portion 27 b and the substrate 25is achieved. It also becomes possible to make the substrate 25 directlyabut against the housing 3 etc. to dissipate heat.

The display device 1 has the light emitting element 23, the light guideplate 15 which the light from the light emitting element 23 enters, thedisplay panel 9 to which the light of the light guide plate 15 isirradiated, and the wirings 17 which extend from the light emittingelement 23 side along the edge of the light guide plate 15 (second sidesurface 15 bc or third side surface 15 cd) and which supply power to thelight emitting element 23. The light guide plate 15 has the stopper 15 swhich is located on the arrangement side of the wirings 17 from thelight emitting element 23 and which restricts the movement of the lightemitting element 23 to the arrangement side of the wirings 17.Accordingly, in the display device 1 as well, the effect of the lightsource device 11 of the second viewpoint explained above is exhibited.

The present invention is not limited to the above embodiment and may beexecuted in various ways.

The display device is not limited to a liquid crystal display device.For example, the display device may be one which has a film which isilluminated by a light source device (device in which the image does notchange) as well. Further, for example, the display device may be anorganic EL display device as well (the display panel may be an organicEL panel as well). The organic EL panel is a self-light emitting type,therefore a backlight etc. (a light source device including a lightguide plate) is unnecessary in the image display itself. However, byilluminating the organic EL panel, the overall visibility can beimproved. Note that, in the case where the display panel is an organicEL panel, the display region thereof may be provided offset with respectto the major surface of the light guide plate and the guide parts may beformed along the edge having a large distance from the display regionamong the edges of the light guide plate in the same way as the casewhere the display panel is a liquid crystal panel. Further, the displaydevice may be one configuring a touch panel as well.

The number of light sources is not limited to two. One or three or morelight sources may be provided as well. Further, the light source is notlimited to one arranged at the corner of the light guide plate. Forexample, the light source may be provided at the center of one side ofthe light guide plate as well. The light source is not limited to an LEDand may for example be a cold cathode tube.

The wirings and guide parts for positioning the wirings may be arrangednot only in the non-irradiation region of a light source or a regionwhich has a relatively large distance from the display region, but alsoin the irradiation region or a region which has a relatively shortdistance from the display region. Note that, by arranging light sourcesat four corners of the light guide plate, etc., there need not be anon-irradiation region. By arranging the display region at the center ofthe light guide plate, there need not be a region having a relativelylarge distance from the display region.

The guide part is not limited to one having a groove portion capable ofaccommodating the wiring. For example, the guide part may be onepositioning the wiring by a plurality of pins which are arranged alongthe extending direction of the wiring.

The groove portion configuring the guide part is not limited to aconcave groove and may be a groove with a hole as well. Further, thegroove portion is not limited to one provided in the major surface ofthe light guide plate and may be one provided in a side surface of thelight guide plate.

The first locking portions and second locking portions (31 d, 31 e)which are alternately arranged in the extending direction of the wiringsare not limited to those abutting against the side surfaces of thewirings in the direction faced by the major surface of the light guideplate and may be those abutting against the side surfaces of the wiringsin the direction along the major surface of the light guide plate.

Further, the first locking portions and second locking portions do nothave to configure the first concave grooves (31 b) and second concavegrooves (31 c). For example, in the embodiment, the third lockingportions 31 j (FIG. 10 and FIG. 11) may be omitted as well. Note that,in this case, the wirings can be locked by the first locking portions 31d and second locking portions 31 e from the lateral side of the lightguide plate 15, therefore the slit 31 s is unnecessary.

Further, in the case where the first concave grooves and second concavegrooves are formed, a locking portion for suppressing detachment of thewirings 17 from these concave grooves may further be provided as well.For example, in FIG. 10, a locking portion which projects from the endof a third locking portion 31 j on the upper side in the sheet surfaceto the inside of the first major surface 15 e and closes a portion ofthe lateral side of a first concave groove 31 b may be provided as well.Further, for example, in FIG. 11, a locking portion which projects fromthe end of a second locking portion 31 e on the slit 31 s side to thesecond major surface 15 f side may be provided as well.

Further, the gap (d) between a first locking portion and a secondlocking portion seen in the extending direction of the wiring may bebroader than the diameter of the wiring as well. Even in this case, theeffect of positioning on one lateral side and the other side of thewiring is obtained.

The number of the first locking portions and second locking portions(first concave grooves and second concave grooves) is not limited tofive in total. For example, it may be two in total (one first lockingportion and one second locking portion). Note, it is preferred from theviewpoint of obtaining a sufficient positioning effect that there bethree or more first locking portions and second locking portions intotal.

The projection portion (31 g) around which the wiring is circled is notlimited to one which makes the wiring turn back. For example, it may beone changing the direction of the wiring by about 90 degrees as well.Further, the case where the wiring turns back is not limited to the casewhere the orientation of the wiring changes by 180 degrees and mayinclude a case where the orientation of the wiring changes by 135degrees to 225 degrees or changes by 150 degrees to 210 degrees.Further, the wiring may be wound around the projection portion by onelap or more.

Further, the projection portion around which the wiring is circled isnot limited to one projecting to the direction faced by the majorsurface of the light guide plate. For example, the projection portionmay be one projecting to the direction faced by a side surface of thelight guide plate as well. Further, the shape of the projection portionis not limited to a rectangular parallelepiped shape. For example, theprojection portion may be a cylindrical shape or may be a tapered shapewith a diameter which expands toward the tip end side.

The optical sheet and reflecting plate (or reflecting sheet) may beomitted, the other members may be used instead of them, or portionsexhibiting these functions may be formed integrally with the light guideplate.

The substrate on which the light emitting element is mounted and theheat dissipating plate which holds the substrate may be omitted as well.That is, the light emitting element may be positioned directly withrespect to the light guide plate. The empty space of the heatdissipating plate is not limited to a hole and may be a cut-away portionor concave portion.

REFERENCE SIGNS LIST

-   -   1 . . . display device,    -   11 . . . light source device,    -   13 . . . light source unit (light source),    -   15 . . . light guide plate,    -   17 . . . wiring,    -   23 . . . light emitting element (light source),    -   31 . . . guide part, and    -   15 s . . . stopper.

1. A light source device comprising: a light source, a light guide platewhich light from the light source enters, and wiring which extends fromthe light source side along the edge of the light guide plate andsupplies power to the light source, wherein the light guide plate has astopper which is located on an arrangement side of the wiring from thelight source and which restricts movement of the light source to thearrangement side.
 2. The light source device as set forth in claim 1,wherein: the light guide plate has a positioning portion which islocated on the opposite side to the arrangement side of the wiring fromthe light source and restricts movement of the light source to theopposite side.
 3. The light source device as set forth in claim 1,wherein: the light guide plate has a projection portion around which thewiring circles so that the wiring which extends from the light sourceside is turned back to the light source side.
 4. The light source deviceas set forth in claim 3, wherein: the projection portion is provided ina non-irradiation region of the light source.
 5. The light source deviceas set forth in claim 3, further comprising: an optical sheet which islaminated on one major surface of the light guide plate, wherein thelight guide plate is formed in the one major surface with a concavegroove which accommodates the wiring, the projection portion isconfigured in a partial region of the one major surface by extension ofthe concave groove so as to separate the partial region from the otherregions, and the optical sheet closes the concave groove.
 6. The lightsource device as set forth in claim 1, further comprising: a substrateon which the light source and the wiring are mounted and a heatdissipating plate which holds the substrate, wherein the stopper abutsagainst the heat dissipating plate to restrict movement of the lightsource.
 7. The light source device as set forth in claim 6, wherein: theheat dissipating plate has an extending portion which is located on oneside of the direction faced by the light guide plate further than thelight guide plate and extends parallel to the light guide plate, and theextending portion is formed with an empty space which accommodates atleast a portion of the substrate.
 8. A display device comprising: alight source, a light guide plate which light from the light sourceenters, a display panel to which the light of the light guide plate isirradiated, and wiring which extends from the light source side alongthe edge of the light guide plate and which supplies power to the lightsource, wherein the light guide plate has a stopper which is located onan arrangement side of the wiring from the light source and whichrestricts movement of the light source to the arrangement side.